The aim of this study was to investigate the impact of management information system on employees’ performance of Tehran Province Water and Wastewater Company in district 5. The present study was an applied research in terms of purpose and a descriptive correlational survey in terms of method. Cochran's formula was used to determine sample size which was 219 employees. The statistical sample was selected using simple random sampling. A standard questionnaire was distributed among them to answer the questions. Some experts were asked to give their opinion on the face validity of the questionnaire. The reliability of the questionnaire was examined using Cronbach's alpha test. The data were analyzed using linear regression test. The results indicated that management information system affects employees’ performance, decision-making, and reducing time of activities in Tehran Province Water and Wastewater Company in district 5. Friedman test results to rank the impact of management information system on employees’ performance indicated that performance of employees is the first priority in terms of effectiveness.
